BAR 3751075 - Caterpillar

Fuel System Reference - Publications and Parts
ReferenceOperation & Maintenance, SEBU7651ReferenceDisassembly & Assembly, RENR2276ReferenceDiesel Fuels & Diesel Fuel Systems, LEBW4976ReferenceSpecifications, SENR3130ReferenceCaterpillar Dealer Contamination Control Compliance Guide, PEBJ0002Basic Torque Knowledge
When a steel fitting is properly torqued, it is stretched to an elastic state known as elastic deformation, which provides the necessary clamp load. When the fitting is loosened, it returns to its original length, size, and shape. A connection may be tightened numerous times without damaging the joint.If a fitting is over torqued, it can be stretched beyond its elastic state into what is known as the plastic state and will not return to original size or shape. This process is known as plastic deformation. When the fitting has been stretched out or permanently deformed, the clamp load is significantly reduced. Additional tightening at the joint may result in damages.Generally speaking, the specified torque values consume approximately 70 percent of the fasteners total limit of elasticity. The remaining 30 percent is a safety margin. Stretching a fitting to its limit, or beyond, causes the fitting to lose its elasticity, resulting in a loss of clamping force. It is important to always refer to Caterpillar torque specifications.Torque Tools and Calibration
Torque wrenches are precision instruments that require specified inspections and calibration processes. Every torque tool should be permanently marked with a unique identification number and a torque value for that specific wrench.The frequency of inspection and calibration may vary from shop to shop, however, the technician is ultimately responsible for ensuring the correct torque tool is used and a valid calibration decal is present. When using a torque wrench, hold the handle of the torque tool in the proper location. Always use a steady pulling motion in the tightening direction. Both preset and adjustable torque wrenches break over center and make a crisp clicking or snapping sound when the torque value is reached. The technician must stop pulling as soon as the wrench clicks and never "double click" the joint for "good measure".Technicians should also avoid using a torque wrench to loosen a joint that it did not tighten, as this may damage the tool and possibly void the calibration.Changing the length of an attachment greatly affects torque output; therefore, technicians should never modify a torque tool by adding different length extensions, sockets, or attachments. Remember, the technician is ultimately responsible for applying the correct torque.STOR & ORFS Fittings
Straight Threaded O-Rings (STOR)
O-Ring Face Seal (ORFS)STOR and ORFS fittings are designed with grooves for o-ring seals to be located. When properly installed, the o-ring seals produce a leak free assembly by establishing a tight and even seat with the adjacent component.Special tooling is available through Caterpillar that protects the seal from damage by the machined threads during sub-assembly. By eliminates the need to roll o-rings over machined threads, leaks from nicks, cuts, gouges and twisted o-rings are virtually eliminated.Prior to final assembly, inspect the seals, fittings, and tooling for damage or debris. A quick visual review will help identify the vast majority of